阅读说明：本技术 一种竖井结构及其施工方法 (Vertical shaft structure and construction method thereof ) 是由 杨光华 陈富强 李支令 杜秀忠 贾恺 李长江 于 2020-05-19 设计创作，主要内容包括：本发明公开了一种竖井结构及其施工方法,竖井结构包括支挡结构,支挡结构包括盾构隧道、内衬支护结构和长短结合的地下连续墙。设计长短结合的地下连续墙,当开挖至短的地下连续墙底时,即短的地下连续墙吊脚时,依靠长的地下连续墙的嵌岩段来保证地基承载力和稳定性的要求,当开挖至长的地下连续墙底时,即长的地下连续墙吊脚时,依靠短的地下连续墙结合内衬支护结构的组合结构来满足地基承载力和稳定性的要求,实现分阶段受力的体系。本发明可广泛应用于深基坑施工技术领域。(The invention discloses a vertical shaft structure and a construction method thereof. The underground continuous wall with the combined length is designed, when the underground continuous wall is excavated to the bottom of the short underground continuous wall, namely the hanging feet of the short underground continuous wall, the requirements of the bearing capacity and the stability of the foundation are ensured by the rock embedding section of the long underground continuous wall, and when the underground continuous wall is excavated to the bottom of the long underground continuous wall, namely the hanging feet of the long underground continuous wall, the requirements of the bearing capacity and the stability of the foundation are met by the combined structure of the short underground continuous wall and the lining supporting structure, so that a system with the force applied in stages is realized. The invention can be widely applied to the technical field of deep foundation pit construction.)

1. A shaft structure characterized in that: the shield structure comprises a shield tunnel (13), a lining supporting structure and a long and short underground continuous wall (11).

2. Shaft construction according to claim 1, characterized in that: the lining support structure comprises a lining wall (12), wherein the lining wall (12) is mainly made of reinforced concrete.

3. Shaft construction according to claim 2, characterized in that: the lining supporting structure comprises a ring frame beam, and the ring frame beam is arranged on the lining wall (12).

4. Shaft construction according to claim 1, characterized in that: the lining support structure comprises a plurality of ring frame beams, and the ring frame beams are arranged at intervals along the vertical direction.

5. Shaft construction according to claim 1 or 2, characterized in that: the supporting structure is provided with a locking pin anchor cable (16).

6. Shaft construction according to claim 1, characterized in that: and a capping beam (14) is arranged at the top of the supporting and blocking structure.

7. Shaft construction according to claim 1, characterized in that: and a hanging net concrete spraying protective surface (15) is arranged at the lower rock layer section of the supporting and retaining structure.

8. A construction method of a vertical shaft structure is characterized by comprising the following steps:

s-1, leveling a field, digging a guide channel and building a guide wall (21);

s-2, digging a groove, hoisting a joint pipe (22) and a reinforcement cage (23), pouring concrete and pulling out a connecting pipe to form a wall, and repeating the steps until the construction of the underground continuous wall with all long and short combinations is completed;

s-3, excavating earthwork in the vertical shaft in a layered mode, and constructing a reinforced concrete lining wall or a ring frame beam in a reverse mode;

s-4, excavating earthwork of a rock layer section in a layered mode until the earthwork reaches the bottom of a pit, and constructing spray anchor soil nails according to the sequential operation;

and S-5, pouring a vertical shaft bottom plate according to the lining wall of the sequential rock layer section.

9. The construction method of a shaft structure according to claim 8, wherein: and step S-3, additionally arranging a locking anchor cable or a ring frame beam at the wall foot of the short underground continuous wall.

Technical Field

The invention relates to the technical field of deep foundation pit construction, in particular to a vertical shaft structure and a construction method thereof.

Background

At present, a deep foundation pit lifting foot type supporting structure under geological conditions of upper soil and lower rock is very widely applied, if the end part of the supporting and retaining type structure is embedded into strongly weathered or moderately weathered rock, particularly when the rock strength is high, the construction grooving difficulty is very high, so that the construction efficiency is reduced and the cost is increased, and the depth of the general embedded rock is limited by considering the economical efficiency and construction factors. If the bottom surface of the foundation pit is positioned below the bedrock, when the foundation pit is excavated to the basement, the supporting and blocking type structure is suspended in the air, namely a 'hanging foot'. The structure of the existing foot-hanging type supporting structure generally adopts a foot-hanging type filling pile or an underground continuous wall combined locking prestressed anchor cable, an upper soil layer part is generally a filling pile or an underground continuous wall combined prestressed anchor cable or an inner supporting structure, a lower rock stratum is generally supported by a spray anchor, and in order to ensure the stability of the end part of the foot-hanging structure, a rock shoulder with the width of 1-3 m is generally reserved for supporting a pile foot or a wall foot.

However, the design and calculation theory of the current hanging-foot type supporting structure is not mature. During the design and construction of the hanging foot pile, due to the limitation of building space, the width of the reserved rock shoulder cannot be too large, so that the embedding force of the hanging foot pile on the pile foot or the wall foot is limited, and an anchor cable is added at the pile foot or the wall foot to make up the deficiency of the embedding force of the rock shoulder during the general design. The existing foot-hanging type supporting structure has the limitations and disadvantages that the end parts of cast-in-place piles or underground connecting walls are at the same elevation, the end parts of the retaining structure have the problems of local instability, insufficient bearing capacity and the like, in addition, if a foot-locking anchor rope fails, the structure system fails, and the safety and success or failure of the engineering completely depend on the reliability of the foot-locking anchor rope.

Disclosure of Invention

In order to solve at least one of the technical problems and ensure the bearing capacity and stability of the support, the invention provides a vertical shaft structure and a construction method thereof, and the adopted technical scheme is as follows:

the shaft structure provided by the invention comprises a retaining structure, wherein the retaining structure comprises a shield tunnel, a lining supporting structure and a long and short underground continuous wall.

In some embodiments of the invention, the lining support structure comprises a lining wall, the lining wall being constructed primarily of reinforced concrete.

In some embodiments of the invention, the lining support structure comprises a ring frame beam, the ring frame beam being provided on the lining wall.

In some embodiments of the invention, the lining support structure comprises a plurality of ring frame beams, each ring frame beam being vertically spaced apart.

In some embodiments of the invention, the retaining structure is provided with a locking anchor cable.

In some embodiments of the invention, a capping beam is provided on the top of the retaining structure.

In some embodiments of the invention, the lower rock layer section of the retaining structure is provided with a net-hanging concrete-spraying protective surface.

The construction method of the vertical shaft structure provided by the invention comprises the following steps:

s-1, leveling a field, digging a guide channel and building a guide wall;

s-2, digging a groove, hoisting a joint pipe, hoisting a reinforcement cage, pouring concrete and pulling out a connecting pipe to form a wall, and repeating the steps until the construction of the underground continuous wall with all long and short combinations is completed;

s-3, excavating earthwork in the vertical shaft in a layered mode, and constructing a reinforced concrete lining wall or a ring frame beam in a reverse mode;

s-4, excavating earthwork of a rock layer section in a layered mode until the earthwork reaches the bottom of a pit, and constructing spray anchor soil nails according to the sequential operation;

and S-5, pouring a vertical shaft bottom plate according to the lining wall of the sequential rock layer section.

In some embodiments of the invention, in step S-3, anchor bolts for locking feet or ring frame beams are additionally arranged at the wall feet of the short underground continuous wall.

Has the advantages that: the underground continuous wall with the combined length is designed in the shaft structure, when the underground continuous wall is excavated to the bottom of the short underground continuous wall, namely the hanging feet of the short underground continuous wall, the requirements of bearing capacity and stability of a foundation are ensured by depending on the rock embedding section of the long underground continuous wall, when the underground continuous wall is excavated to the bottom of the long underground continuous wall, namely the hanging feet of the long underground continuous wall, the requirements of bearing capacity and stability of the foundation are met by depending on the combined structure of the short underground continuous wall and the lining supporting structure, and a system with the force applied in stages is realized. The invention can be widely applied to the technical field of deep foundation pit construction.

Drawings

Fig. 1 is a schematic plan view of a shaft structure, in which a circular shaft is taken as an example;

FIG. 2 is a cross-sectional view A-A of the structure of FIG. 1;

FIG. 3 is a schematic view of the working conditions of digging and guiding the trench and constructing the guiding groove in the construction method;

FIG. 4 is a cross-sectional view B-B of the structure of FIG. 3;

FIG. 5 is a schematic view of the working conditions of trenching in the construction method, wherein the left side of the figure is a poured trench section and the right side is an unearthed trench section;

FIG. 6 is a top view of the structure of FIG. 5;

FIG. 7 is a schematic view of the working conditions of the construction method for hoisting and placing the joint pipe, wherein the left side of the drawing is a poured groove section, and the right side of the drawing is an trenchless groove section;

FIG. 8 is a top view of the structure of FIG. 7;

FIG. 9 is a schematic view of the working conditions for hoisting and placing the reinforcement cage in the construction method, wherein the left side of the drawing is a poured groove section, and the right side of the drawing is an trenchless groove section;

FIG. 10 is a top view of the structure of FIG. 9;

FIG. 11 is a schematic view of the conditions of concrete pouring in the construction method, where the left side of the figure is a poured groove section and the right side is an unearthed groove section;

FIG. 12 is a top view of the structure of FIG. 11;

FIG. 13 is a schematic view of a construction method in which a joint pipe is pulled out to form a wall, where the left side of the drawing is a poured groove section and the right side is an unearthed groove section;

fig. 14 is a top view of the structure of fig. 13.

Detailed Description

The present invention will be further described with reference to fig. 1 to 14.

The invention relates to a shaft structure, which comprises a supporting and retaining structure, wherein the supporting and retaining structure comprises a shield tunnel 13, a lining supporting structure and a long and short combined underground continuous wall 11, and the shaft structure uses the long and short combined underground continuous wall 11 to form a lifting foot type circular shield shaft structure capable of bearing force in stages by taking a circular shaft as an example. The underground continuous wall 11 with the combination of the long and the short sections mainly plays a role in retaining soil and guarantees the bearing capacity and the stability of a soil layer section on the upper portion of the retaining structure, and in order to prevent the safety stability of the retaining structure from being affected due to the fact that the hanging feet appear on the underground continuous wall 11 at the same elevation, namely the safety stability of a vertical shaft is prevented from being affected, the lining supporting structure and the underground continuous wall 11 with the combination of the long and the short sections are adopted, and the purpose of staged stress is achieved.

The underground continuous wall 11 with the length combined can provide an economic and reliable supporting scheme for a soil-rock combined vertical shaft, the risk that a supporting structure is unstable due to failure of a foot locking anchor cable 16 of a conventional foot hanging type structure is avoided, the problems that the end part of the conventional foot hanging type supporting structure is locally unstable, the bearing capacity is insufficient and the like are solved, rock shoulders are avoided being reserved, and the underground continuous wall has the advantages that a supporting system is clear in stress, easy to construct and realize, easy to guarantee construction quality and the like.

In some embodiments, the lining support structure comprises a lining wall 12, the lining wall 12 is mainly made of reinforced concrete, a reverse lining wall 12 is adopted in the pit, and the lining wall 12 is constructed in a vertical top-to-bottom construction method and mainly plays a role in supporting and guaranteeing the stability of a hanging foot part of the underground continuous wall 11. Further, the lining support structure includes ring frame beams, which are provided on the interior lining wall 12.

In some embodiments, the lining wall 12 is not provided, the lining support structure includes a plurality of ring frame beams, each ring frame beam is arranged along the vertical direction at intervals, and the lining wall 12 is replaced by a structure formed by the plurality of ring frame beams, so that an economic, reasonable and technically feasible support system is formed.

In some embodiments, the lower part of the retaining structure is provided with a locking anchor cable 16, which mainly plays a role in protecting the stability of the hanging foot part of the underground continuous wall 11, and forms a double insurance. The anchor cable 16 with locking legs can be left according to construction requirements, for example: when the hanging feet are arranged on the inner lining wall 12 made of reinforced concrete, the foot-locking anchor cables 16 are seen as temporary use structures during excavation, and after the inner lining wall 12 is constructed, the inner lining wall 12 has the function of replacing the foot-locking anchor cables 16, so that the safety and stability of the vertical shaft are greatly improved.

In some embodiments, the top of the retaining structure is provided with a capping beam 14, which mainly acts to integrally stress the underground diaphragm wall 11 and the interior lining wall 12.

In some embodiments, the lower rock layer section of the retaining structure is provided with a net-hanging concrete-spraying protective surface 15 which mainly plays a role in protecting the slope surface of a salt city at the lower part of the vertical shaft.

A particular embodiment of the hoistway structure is described below with the understanding that the following description is illustrative only and is not intended to be limiting.

The vertical shaft structure comprises a supporting and blocking structure, the supporting and blocking structure comprises a shield tunnel 13, an inner lining wall 12 and a long and short underground continuous wall 11, the inner lining wall 12 is mainly composed of reinforced concrete, and the supporting and blocking structure is provided with a locking anchor cable 16, a capping beam 14, a net hanging concrete spraying protective surface 15, a soil nail 17 and a bottom plate. The interior lining wall 12 is of a stepped two-section structure with a large upper part and a small lower part.

This shaft structure avoids keeping the rock shoulder, when excavate to short underground continuous wall 11 end, when short underground continuous wall 11 hangs the foot promptly, can rely on the requirement that long underground continuous wall 11's the section of inlaying the rock comes assurance foundation bearing capacity and stability. When the long underground continuous wall 11 is excavated to the bottom, namely the long underground continuous wall 11 is hung on the foot, the short underground continuous wall 11 can be used for combining with the combined structure of the lining wall 12 to meet the requirements of the bearing capacity and the stability of the foundation.

A structural system capable of bearing force in stages along with earth excavation is formed by utilizing a long and short combined underground continuous wall 11 and lining wall 12 supporting system, and the state of bearing force in stages is achieved. Along with the excavation, do not keep the rock shoulder, do not establish lock foot anchor rope 16, the ground bearing capacity and the stability of the supporting construction of foot formula of hanging can more guarantee.

The invention also relates to a construction method of the vertical shaft structure, which comprises the following steps:

s-1, leveling a field, digging a guide channel and building a guide wall 21;

s-2, digging a groove, hoisting a joint pipe 22 and hoisting a reinforcement cage 23, pouring concrete and pulling out a connecting pipe to form a wall, and repeating the steps until the construction of the underground continuous wall with all long and short combinations is completed;

s-3, excavating earthwork in the vertical shaft in a layered mode, and constructing a reinforced concrete lining wall or a ring frame beam in a reverse mode;

s-4, excavating earthwork of a rock layer section in a layered mode until the earthwork reaches the bottom of a pit, and constructing spray anchor soil nails according to the sequential operation;

and S-5, pouring a vertical shaft bottom plate according to the lining wall of the sequential rock layer section.

In the step S-2, grooving is performed by dividing the groove section of the underground diaphragm wall, specifically, grooving is performed by the grooving machine 24. In addition, the process of digging the groove arranges the wall protection mud.

In the step S-2, a plurality of the pouring pipes 25 are inserted to pour concrete.

In some embodiments, in step S-3, anchor bolts or ring frame beams are added to the wall footers of the short underground continuous wall to form a double-insurance structure, i.e., a redundant design.

While the embodiments of the present invention have been described in detail with reference to the drawings, the present invention is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present invention within the knowledge of those skilled in the art.